Position indicator for elevator cars



c. SAVAGE 2,728,064

2 Sheets-Sheet l B 2 i R WW E o m n L h M O N .m m c l w F .m m 9 my 5 IWM NN 0,1 #11, 8 l m 72/ V Wfi///// 2 5" Q U 2 Dec. 20, 1955 POSITION INDICATOR FOR ELEVATOR CARS Filed March 14, 1951 Y N! i Dec. 20, 1955 SAVAGE 2,728,064

POSITION INDICATOR FOR ELEVATOR CARS Filed March 14, 1951 2 Sheets-Sheet 2 Fig.3.

EN R Conwell Savage. BYKOZM ATTORNEY United States Patent 2,728,064 POSITION INDICATOR FOR ELEVATOR CARS Conwell Savage, New York, N. Y., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application March 14, 1951, Serial No. 215,461 12 Claims. (Cl. 340-21) This invention relates to notching or stepping motors, j

and it has particular relation to notching or stepping motors as employed for indicating the positions of elevator in accordance with the invention, a drum for indicating a plane transverse to the shaft and is spaced axially along the shaft from the pole faces.

about a desired position.

It is, therefore, an object of the invention to provide an improved notching or stepping motor which is substantially free from undesired oscillation.

it is a further object of the invention to provide a stepping or notching motor for operating a rotatable drum wherein the motor includes a stator having a stationary shaft and a Figure l is a view in front elevation of a push-button station or signal unit embodying the invention;

Offi 2,728,064 CC E'atented Dec. 20, 1955 Figure 2 is a view in cross-sectional elevation of the push-button station or signal unit taken along the line ll-li of Fig. 1;

Figure 3 is an enlarged view in section taken along the line lll II of Figure 2;

sembly suitable for the push-button station or signal unit of Figures 1, 2 and 3;

Figure 7 is a schematic view showing the prior art relationship of electromagnets and armature of a notching or stepping motor;

Figure 8 is a schematic view of the armature and certain of the electromagnets employed in the signal unit of Figures 1, 2 and 3; and

Figure 9 is a view in front elevation of a dual position indicator employing Baum Patent 2,303,423 for descriptions of such position indicators or signal units.

Referring to the unit or push-button drawings, Figure 1 shows a signal station 36C, which may replace the signal unit 36 of the Baum patent. The signal unit 36C includes a face plate 2, which has an opening for reception of a down push button 4,

but, preferably, the down push button 4 is omitted for the lower terminal floor. It will be understood that the signal unit 36C is positioned in the corridor Wall 420, which one of the signal corridor wall for each floor As shown in Figure rectangular box 9, which may be constructed in any suitable manner from sheet material such as sheet steel.

The box has a rear wall 9A, an upper wall 9B, a lower wall 9C, a first side Wall 9D, and a second side wall 9E associated elevator through suitable knockouts (not shown) in the box 9. switches 19 and 21 are positioned for operation by means of the push buttons 4 and 5. The face piate 2 is secured to the support strap 15 by, means of machine screws 2,5, and covers the opening in the Wall 42C which receives the box 9. t

.The support strap 15 has a portion 15A positioned adjacent the rear Wall 9A for the purpose of. supporting a position. indicator. This position indicator includes a notching or stepping motor having a stator 27 and a T010529.

The stator 27 includes a base 31 of soft magnetic material, such as soft steel or sheet iron. The base has two angles 31A, and 31B, which may be bent at right angles fr'o'rn fthe sheet material. These angles are positioned against" the portion 15A of thestrap and are secured thereto by machine screws 33, The base also has an a'ri'glefior stop lfl bent therefrom. The purpose of this step will be set forth below. Notches 31A, 37B, 37C andfifl D are formed in the base tofacilitate the location df 'electrical' connections to the motor.

"The base also has secured thereto in any suitable manner ,(as bymeans of rivets) two insulating blocks 3g and 4lj (15 ig. '[These blocks carry terminal 3913, 41A and 413," which are employed in conducting e1 ica'ljener'gy 'to'the motor. The conductors L+, 133, 1134" l ld ly sioflthe aforesaid Baum patent are illustrated in .Figure 2 as connected to the terminal screws.

Aistationarylshaft 43 '(Figures 3 and ,6) is suitably secured-to th'e'base 31. To'this end, the shaft 43 may have i through enlarged head 43A (Fig, 6), which extends theibaseiia l. A flange 43B on the head engages difefaceof' the base 31, and the head 43Ais upset to rivet the baseli p rality of electromagnets are secured to the base 31 and are distributed uniformly around the shaft. In the present embodiment, six 'electroma'gnets are employed and these have rnagnetizin'g windings or coils 71C to 76C, respectively. As shown more clearly in, Figure 3, thef 'electromagnets have cores, which are constructed of a sort 'rh'agneticfrnaterial such as soft iron or soft steel. For example, the ing 'througlfwhichits corev 73D extends. The core 73D has wip rs piece 73E, which is in the form of a head extending partly over one end of the magnetizing winding. The-carers secured to the base 31' by means of a machine screw 73F, which also may be constructed of soft mag'rieticmaterialf The remaining magnetizing windings and cores are sirnilarin construction. It will ,be' noted thattlfe p'ole'pieces of the cores provide pole faces, which lief in a common plane transverse to the shaft. 43. iThe totem) includes a drum or cup 45, which has a substantially cylindrical peripheral surface 45A, a hollow hu'b'WiS Eh concentric with the peripheral surface, and .a radial' wail 45Ci -The drum may be conveniently molded of any desired material. Preferably, the drum is, molded as" phenblic resi 7 1t willlbefnoted that the opening in the hub 45B.

shaft 43 projects through the To facilitate rotation of the amnion the shaft, a pair'of bearing bushings47 and 49 rotatably receiving the shaft 43. .The. bushings maybe apress fit in the opening of the hollow' hub 45l3. l The drurn'may' be retained on the shaft. in

is {provided for secured to the drum 'by means of rivets 5.4. This of pairs of polar projections p oi'ctionsfopposite sides of the shaft .;can be. aligned.

screws 39A,

thefprojecting portion of the shaft 43 securely to magnetizing Winding 73C has an openas"'-ar't i'ntegral un' fro'm a non-magnetic material, such.

it will be understood thatthe.

with the pole faces at one time. Inasmuch as three pairs of .electrornagnets are employed, the-number of polar projections adopted shouldbe an even number which is not divisible by three. Eight polar projections 77C to 84C (as illustrated in Figures 2 and 4) have been found suitable. These polar projections are uniformly spaced about the axis of the drum. 1 I J Because of, the positioning of the armature and the electromagnets, a substantial thrust force is available wt ich acts between the rotor and the stator in a direction paraiiel to the shaft .43. .This thrust force is utilized in damping or preventing undesired oscillations of the rotor relative to thestator. To this end a thrust bearing is provided which offers a sufficient amount of friction to relative movement of thefrotor and stator to prevent undesired movement of the rotor away from a desired position. Conveniently, the bushing 49 may have a flange 49A, which extends over the lower end of the hub 458 (as viewed in Figures 3 and 6) and serves as one member of the thrust bearing assembly. Thesecond member of t e assembly comprises a washer 55. The third member.

comprises the shaft flange 4313. The washer develops s'ufficient friction with the bushing flange and with the shaft flange to prevent undesired oscillations of the rotor relative to the stator. Various materials may be employed in such a thrust bearing assembly. For example, the bushing 4? maybe of brass, bronze, or steel, and the washer 55 may be ofleather or'of conventional brake or clutch facing compositions. In a preferred embodi men't of'the invention, it has been found that a bushing 49 of silicon bronze and a washer 55 of carbon and a a Shore-"Durorneter hardness of 77., Such material is available on the market.

The" shaft 43 preferably isconstructed of a stainless steelg-"such as one containing thirteen percent of chromium by weight. to therotationof thefrotor relative to the stator under the influence of vibration, andprevents the drut'n from c'r'eeping' when the coils are not energized. As previously pointed out the friction introduced by assembly when the coils are-energized is sufficient .to hold the rotor assembly in a desired position without undue oscillationformovement under the influence 'of vibration-l p 'l Preferably, the washer 55 is free to rotate on the shaft 43. -:If-' the-washer is;free torotate andif the parts ar constructed-m illustrated of the I Washer 55 rotates at rate substantiallyless than that of the bushing relative tothe shaft. For examplefthe washer may rotate at approximately o'nehalf the rate of rotation of the bushing' -Tlie d'rum*45 has engraved or otherwiseapplied to its peripheral surfacesuitable indicia representative of the fioors se'rved by the associated 'elevator car. For example,

as-"sl1o'\vn"in' Figure 5, the indicia B; 1, 2 and? are e'n-.

across; the glass being s'eculredin positio-n by a mask plate having an opening, which definesthe portion-got the drum whict i ..is; available for'}obsei yation The pot-.11

If desired, slight be added to the washer material a shearjstrength of 4,3001): s.";i.,"a tensile strength of 1,000 p. s. i. and" The radial bearing offers a slight resistance.

the thrust. bearing preferred materials, the

tion of the drum which is available for observation is are displaced in either a clockwise or counterclockwise represented in Figure by a broken line. direction from the positions illustrated in Figure 7, the

With the proportions herein illustrated, the drum is resultant force produces a torque acting to return the rotated through an angle of 15 for each notch or step rotor into the position illustrated in Figure 7. thereof. For this reason, the successive indicia on the 5 Let it be assumed next that the windings 72C and 75C face of the drum may be spaced from each other about are deenergized and that the wlndings 73C and 760 are the was of rotatlon of the drum by an angle of 15 energized Since the last-named two windings are closest Although the drum rarely will be out of step with the to the polar pro ections 84C and 80C the resultant force elevator it is a s mpl m tt r {0 pro ide t dr m acting between the rotor and stator acts to move the rotor with an automatic registering device. As shown in Figure i to a position whe ei the ola oje tio 80C and 4, the drum is provided with a plurality of openings 57, 4C me i alignment w th the windi g 73C and 76C WhlCh are spaced uniformly about the axis of the drum. sh d h wlndlngs 73 and 75 ther afte be deener- These openings extend through the radial wall 45C in a i d d th w nd ngs 71C a d 740 be gized, th direction parallel to the axis of rotation of the drum. rotor again would he stepped 15 to bring the polar pro- Since the drum r t es 15 f r h p. the Openings 15 jections 77C and 81C into alignment with the windings are Spaced from each other y This means that 71C and 74C. In this way, the successive energizations of twenty-four openings are distributed uniformly around n f wj dj the axis of the drum.

In order to limit the movement of the drum to a Rotation of the rotor inareverse direction also may be predetermined are, eel pp SeTeWS 59A and 5913 may obtained readily; for example, if the rotor occupies the be inserted through Certain of the Openings The position illustrated in Figure 7, energization of the Wind Screw A CQOPeIEteS With the p 35 i0 define the upper ings 71C and 74C rotates the rotor 15 in a counterclockviewed in Figure 4), the screw 59A engages the stop 35 applied to the rotor of Figure 7 in the manner set forth in the aforesaid Baum patent. Although such a brake ma beemloedi the b 35. If the drum 45 is displaced clockwise from the posty p y n em odlmenhot Figures 1 to It tion which it should occupy, the screw 598 will engage the stop during downward movement of the elevator car to reset the drum as the elevator car approaches the 40 with reference to F1 ire 8. I F 8 t 5 sub-basement floor. The specific holes into WlllCh the g n e he armature 3 screws 59A and 59B are inserted depend upon thle num magnets having windings 72C and 750 In Order to her and arrangement of the floors. In each case t ey are M the fi Ur e, the em 1m 1 t inserted to define the limits of movement of the drum 45. p y g r a mg 6 ec lomagnets have It will be appreciated that the size of the signal unit may be varied in accordance with requirements. The various in a similar manner, when the elevator car is at the 35 In considering the operation of the signal unit, it will ure 7. In Figure 7 the armature 53 is illustrated in as sociation with the electromagnets. However, the electromagnets have been rotated 90 from their normal positions and are illustrated as surrounding the armature 53. 55 The polar projections 77C to 84C correspond to the armait the polar ro'ections 79C and 83C are ali ed with mm faces 77 8 respectlvely of the afol'esald B the windings 75C hnd 75C, the resultant force c ting bepatent Wmdmgs 71C in 76C h d respectively tween the rotor and stator of Figure 8 is parallel to the to the w1nd1ngsl71w to 76w of the aroresaid Baum patent aft 43 This force develops a thrust which is absorbed and are similary connected and energized. bv mg th St bea 9 It will be assumed first that the windings 72C and 75C r nng compnsmg the bushl-ng 4 the are energized in series. Although these windings could be energized from an alternating-current source, preferably they are energized from a direct-current source to provide polarities as indicated by the marks S for south pole and 5 N for north pole. If energized by alternating current, the

43 decreases. Consequently, the thrust is a maximum when the polar projections occupy a desired position in alignment with the windings 7 C and 75C.

Because of the variation in the thrust, the thrust vator installations, the windings conveniently may be designed for a normal energizing voltage of 61 2 V0 stator. When the rotor is displaced from this desired each. I position, the thrust bearing offers a relatively small Since the Polar proleehehs 79C and 33C aligned braking etfort to rotation of the rotor relative to the with the windings 72C and 75C the resultant force actstator mg between the rotor and stator to produce rotation has As the rotor 53 1S displaced from the position 111118- a value of zero. As the polar projections 79C and 83C 75 trated in Figure 8 about the shaft 43 component is introduced which acts between. the rotor and t ion, This second force componenta'produces-"a torque acting abouttheshaft 43:.to return the'rotor'into' the desired position, with-respect to' the; stator." The force component which :produCesythe torque alsovaries with the; position of -:the. rotorin a direction opposite to thevariatiom of,-- the "thrustvforce; "Because of these variationsrin the, thrust force and-a torque, an unusually,

9 is displaced to the left relativeto thestrap 15D to permit the mountingof-a second notching motor I on theisamestrap The notching motor 3 is similar to the notching motor H except'that it isireversed relative to the motorH abou't a line transverse to the axis of rotationrof thc rotors of the motors. Each of the motors of;Figure.9 would be associatedwith "a' separate one offtheiftwo elevtaors in substantially the same manner. Preferably, the connections are so arranged that'the twol'drurns are actuated in the same direction about their common axis of, rotation when thetwo elevator cars move in the same direction. 'A box and a face plate may be provided for the motors of Figure 9, which are similar to those illustrated in'Figures l and 3, except for an increase in width, It .will be understood that the face plate employed for theunit illustrated in Figure 9 would have, a ,separate windowfor eaeh of the drums. The construction ofrFigureI9 permits the stator assemblies to be located substantially over the strap 15]) and permits connections to themotors to be located between the two motors Althoughthe invention has been described with reference to certain specific embodiments thereof, numerous modifications falling .within the spirit and scope of :the invention are possible. i

I claim ,as my, invention;

1. In a notching motor, a stator. including an even number of pole pieces disposed uniformly about an axis, said pole pieces having polefaces disposedin a common plane transverse ,to said, axis, a, rotor-ofparamagnetic material disposed for rotation relative to the stator about saidiaxis, said rotor having an even number ofpolar projections disposed unifornily about saidaxis for movement'adjaeent saidpole faces and located in a plane parallel and adjacentto said first-named plane, the number "of said polar projections being selected to permit only two polar projections onopposite sides of the axis to be adjacent said 'pole'faces at any time, said pole pieces-being'divided intoseparate pairs, each of said pairs comprising. two of said pole faces on opposite sides or" said axis, separate means for energizing each of-'-said'pairs to direct magnetic'fiux through the two associatedpole faces and through the. rotor, whereby energization of one or" said pairs results in application of a torqhe acting about said axis and a force acting parallel'to'fsaid axis between said rotor and said stator, a bearing-assembly permitting rotation of the rotor relative to the pole pieces, and a[tn'rust-bearing for resisting movement'of said'rotor relative to the pole pieces .by saidfforce, said thrust bearing comprisinga damping material forrestrictirigmovements of the rotor relative to thestator'under' the influence of intertia.

'2; A motor as defined inclairn- 1 wherein the ends;

of the p'ole'pie'ces opposite to said pole faces are secured to a.paramagneticmember 3. 'A motor asdefined. n claim l in combination with 1 a drumcoupledito saidrotor-for movement about'said axis, said drumlsubstantially surrounding sard'polepreoes'. 4: A motor as defined in claim3 wherei'n said drum has. a hollow hub concentric withthe p'eripheralisurfaceoffthe. drum, said bearing assembly e'ornprising a bearing" shaft secured: to the "stator and projecting within said hub.

' 5. In an indicator device, a rotor, a stator, bearing means mounting the rotor for rotation relative to said stator about an axis, electroresponsivesneansfor apply ing a force between the rotor and the stator formoving' the rotor through afraction of a revolution, said force increasing as. said rotor moves through-said fraction and including a substantial component acting-to produce a "torque about the axis and a substantialcomponent increasing as said rotor moves through'said fraction and acting parallel to said axis to produce-thrust, and a thrust" bearing for receiving said thrust, said thrust b'earingofier ing substantially greater friction than said bearing means -;to5movernent of the rotor away from a desired position relative to the stator.

6. A device as claimed in claim 5 wherein the thrust bearing comprises a first'member secured to the rotor, a second member secured to-the stator and a third member positioned between and engaging said first and second members, said third member being-rotatable relative to the -rotor and the stator about said axis.

7. A-device' as claimed in claim S-Wherein the thrust bearing comprises amember substantially constructedof carbon and coacting members constructed substantially of silicon bronze and 'of stainless steel for engaging the carbon member.

8. In a notching'motor, a stator including an even number of pole pieces disposed uniformly about an axis-said pole pieces having pole faces disposed in a common plane transverse to said axis, a rotor ofparamagnetic material disposed for-rotation relative to the stator about said axis, said rotor having an-even nurnberof polar pro jections disposed uniformly about said axis for movement ,,adjacent said pole faces and located in a plane parallel and adjacent to said first-named plane, the number of said polar projections being selected to permit only two polar projections on opposite sides of the axis to be adjacent said pole faces at any time, said pole pieces being -divided into separate pairs, each of said pairs comprising two of said pole faces on opposite sides of said axis, separate means for energizing each of said pairs to direct magnetic flux through the two associated pole faces and through the rotor, whereby energization of one of said pairs results in application of a torque acting about said axis and a force acting parallel to said'axis' between said rotor andsaid stator, a bearing assembly permitting rotation of the rotor relative to the pole pieces, and a thrust bearing for resisting movement of said rotor relative" to the pole pieces'by said force, said thrust bearing com: prising a thrust receiving member interposed between the stator and the rotor-for damping and-restricting movements of the rotor relative to the stator under the influence ofinertia, said thrust receiving member being constructed of a carbon friction material.

9. In a notching motor, a stator including an even number of pole pieces disposed uniformly about an axis,

said pole pieces having pole faces disposed in a common plane transverse to said axis, a rotor of paramag netic material disposed for rotation relative to the stator about said axis, said rotor having an even number of polar projections disposed uniformly about said axis for movement adjacent said pole faces and located in -a planeparallel and adjacent to said first-named plane, the number of said .polar projections being selected to permit only two polar projections on opposite sides of the axis to be adjacent said pole faces at any time, said pole pieces.

being divided into separate pairs, each of said pairs comprisihg'two of said pole faces on'opposi'te sides of' said axis, separate means for energizing each of said pairs to direct magnetic flux through the two associated pole faces and through the rotor, whereby energization of one of said pairs results in application of a torque acting about said axis and a force acting parallel to said axis between said rotor and said stator, a bearing assembly permitting rotation of the rotor relative to the pole pieces, and a thrust bearing for resisting movement of said rotor relative to the pole pieces by said force, said thrust bearing comprising a material for restricting the rotor relative to the stator.

10. In an indicator device, a pair of cup-shaped drums each having indicia angularly spaced about the axis thereof, means mounting the drums for independent rotation adjacent each other about a common axis, said drums bethe drums about its axis, each of means being drum, each ated drum adjacent the end Well of such associated drum, pole piece means located substantially withsubstantially in the space between the drums.

12. In an indicator device, a rotor unit including a drum having indicia spaced angularly about the drum axis and having an integral hollow hub concentric with the surface of the drum, said hub being substantially within the drum, a stator unit. bearing means including a shaft secured to the stator unit, said shaft extending into the hoilow hub, said heating means mounting the rotor for rotation about said shaft, said stator providing an in dicia station adjacent the rim or" the drum, notching motor means located substantially Within said drum for notching the drum about the shaft to selected positions relative to the stator unit for successively positioning said indicia at said station, and adjustable stop mechanism positioned substantially within the drum for defining limits of rotation of the rotor unit relative to the stator unit, said stop mechanism comprising first and second stop elements positioned on a first one of said units and independently adjustable about said axis, and stop means secured to a second one of said units intermediate said stop elements, said step means engaging the first stop element to limit rotation or" the rotor unit relative to the stator '5 in a first direction, and said stop means engaging the second stop element to limit rotation of the rotor unit in a second direction.

References Cited in the file of this patent UNITED STATES PATENTS 155,396 Van Hoevenbergh Sept. 29, 1874 515,216 Gutrnann Feb. 20, 1894 540,456 Pearce June 4, 1895 1,058,545 Caldwell Apr. 8, 1913 1,229,785 Proebstel June 12, 1917 1,501,497 Schwarz July 15, 1924 1,502,840 Beard July 29, 1924 1,504,609 Crane Aug. 12, 1924 1,778,761 Heising Oct. 21, 1930 1,890,752 Sanford Dec. 13, 1932 1,903,230 Stewart Mar. 28, 1933 1,915,090 Hammond June 20, 1933 2,298,621 Holland-Letz Oct. 13, 1942 2,303,423 Baum Dec. 1, 1942 2,559,339 Blease et a1. July 3, 1951 FOREIGN PATENTS 6,346 Australia of 1932 

